@mixin flex($fg: 1, $fs: null, $fb: null) {
  -webkit-box-flex: $fg;
  -webkit-flex: $fg $fs $fb;
  -moz-box-flex: $fg;
  -moz-flex: $fg $fs $fb;
  -ms-flex: $fg $fs $fb;
  flex: $fg $fs $fb;
}

@mixin circle($r) {
  width: $r;
  height:$r;
  background: transparent; /* Can be set to transparent */
  @include border-radius(100%);
}
